the sealing characteristics and changing characteristics：
1, the valve in the closed activities, first is the completion of the cone valve core and valve combination of independent sealing, i.e. one level sealed.
2, when the valve to continue down the off time, compression spring combination within the cartridge until the combined valve core and valve flap flat plane independent Sealing surface of the seal, grade two.
3, when the valve opens, the two stage seal first detachment, spring recovery, until one level sealed detachment, complete all open.
4, the valve two stage seal, greatly improving the service life of the valve, but also improve the sealing performance of the valve.
5, the valve in the maintenance, can be removed after the direct replacement of the valve cover, valve flap and valve seat, realize the maintenance characteristics of fast.

Chief features and usages：
For steam, water pipe as an opening and closing device.
Two, applicable situation:
it is Suitable for the thermal power plant drainage etc. sealing performance of valve occasions with high requirements.
Three, structural characteristics:
Independent valve 1, the valve core and the movable combination, with two levels of sealing structure of conical and planar composition.
Independent valve 2, can easily realize rapid site maintenance and replacement.